Virginia’s 2018 mosquito season is proving to be one of the worst in years, animal health officials say. | Photo: iStock

Virginia’s 2018 mosquito season is proving to be one of the worst in years, animal health officials say. Recent deluges of rain have created stagnant pools of water perfect for mosquito breeding while cooler temperatures have helped to slow the maturation of larvae, delaying the pests’ season this year.

“Now it has hit in full force, and horses are at risk of contracting mosquito-borne diseases such as Eastern equine encephalitis (EEE) and West Nile virus (WNV),” said Charles Broaddus, DVM, Virginia Department of Agriculture and Consumer Services (VDACS).

A viral disease, EEE affects the central nervous system and is transmitted to horses by infected mosquitoes. Clinical signs of EEE include moderate to high fever, depression, lack of appetite, cranial nerve deficits (facial paralysis, tongue weakness, difficulty swallowing), behavioral changes (aggression, self-mutilation, or drowsiness), gait abnormalities, or severe central nervous system signs, such as head-pressing, circling, blindness, and seizures. The course of EEE can be swift, with death occurring two to three days after onset of clinical signs despite intensive care; fatality rates reach 75-80% among horses. Horses that survive might have long-lasting impairments and neurologic problems